Call them "the nucleus". An as-yet still undefined group of players who will be this decade's star players for the Houston Astros. Many are still in the minors and could be years away from arriving at Minute Maid Park. Some will be disappointments and some will seemingly rise from nowhere to fill a void. A few may someday become trade bait in order to lure a veteran "last piece" from another club.

With this column, I'll try to identify and rank the most likely players in "the nucleus" along with their positions and current ages. The ranking is from most likely to have an impact to least likely. To decode what's after the name, think position, age, level and how acquired.

1. Jordan Lyles (SP, 20, ML, D08) - Since he's been in Houston longer than many of his new teammates, it may go unnoticed that he's still among the youngest in the group. Don't look at the W-L record or even his sub-5.00 ERA. He's still a work in progress. Once he learns some finer points about being a control pitcher in the majors, he'll be a solid mid-rotation starter for quite some time.

2. Jose Altuve (2B, 21, ML, FA) - Like the Eveready Bunny, he just keeps hitting and hitting. The little Venezuelan was not considered a top prospect before his meteoric rise through the minors but he is making believers at every stop. There will be some adjustments along the way (a recurring theme for all of them) but he projects to be the next fan favorite in Houston with his play, hustle and underdog size.

3. Jonathan Singleton (1B, 19, A, T11) - He's got one of the larger hills to climb to get to the majors but he could be the surest to find stardom some day. Singleton not only has a great swing, he punishes the balls he hits. Of all the players recently acquired in Ed Wade's trading binge, this guy is the one I feel most confident will make a name for himself.

4. Paul Clemens (SP, 23, AA, T11) - Already dominating in Corpus Christi, the righthander acquired in the Michael Bourn deal will probably make his debut next season. He hasn't allowed an earned run in his first three starts with the Hooks. Though no relation, I'm sure he'll be asked repeatedly about what it's like being Roger's son.

5. J.D. Martinez (OF, 24, ML, D09) - The mid-season call-up may yet lead the Astros in home runs this season if he keeps up this pace. The two questions with him will be the health of his knees and whether he can continue to hit with power once the book develops on him. For now, he's making a big impression.

6. Jason Castro (C, 24, ML, D08) - Let's not forget this player who has been out all season with a knee injury. If he returns to form next year and improves at the plate (.205 average, .573 OPS in 2010), his play will be critical to the team's success. There are no catchers in the minor league system with his kind of upside.

7. George Springer (OF, 21, TBD, D11) - A five-tool outfielder who just signed last week as the 11th overall pick in the draft, he'll be given every chance to rise quickly through the system and hold down center or right field for the next decade. He'll be another key piece in the franchise's rebuilding efforts.

8. Jarred Cosart (SP, 21, AA, T11) - Perhaps the hardest thrower in the organization, the young Texan who was acquired with Singleton in the Hunter Pence trade, may one day be the Astros' rotation ace or their bullpen closer. Health and control are two key questions with him, as are the issues one always sees as live arms rise through the minors.

9. Jimmy Paredes (3B, 22, ML, T10) - Some said he wasn't ready when he was called up this month from AA. He's been better than expected (.290 average, .785 OPS through Saturday) but the questions are whether he can sustain that, whether he can add enough power to stay at 3B and whether he'll be good enough with the glove to stick.

10. Bud Norris (SP, 26, ML, D06) - He may still have a long stay in Houston ahead and he shows gradual improvement each season as he progresses but if the rebuilding take too long, Norris may be shopped for younger players or leave in free agency. Or he may someday be seen as the "old man" in the Astros rotation.

After this group, the prospects get a bit dicier but here are the next ten to consider:

11. Brett Wallace (1B, 24, ML, T10) - He'll turn 25 next week and has had his moments in the majors but the opportunity may close quickly if he doesn't find his power stroke and doesn't learn how to hit lefties.

12. Domingo Santana (OF, 20, A, T11) - The last player in the Pence trade, this is another raw toolsy Dominican who is still learning his craft. Just imagine, though, if Singleton, Cosart and Santana all become big league stars how internet wags will praise Wade for this deal. Or praise the guy that comes after him.

13. Dallas Keuchel (SP, 23, AAA, D09) - He's struggled so far at Oklahoma City after an All-Star nod in Corpus, he could still be the best lefthander in the system and it is hard to underestimate what that adds to his value.

14. Mike Foltynewicz (SP, 19, A, D10) - Hard to tell what "Folty" develops into but he has a live arm and a lot of time ahead of him. A bullpen role may eventually be his calling.

15. Jonathan Villar (SS, 20, AA, T10) - The batting stats are a bit disappointing but he is the youngest player in the high minors. A product of the Roy Oswalt deal, is he being pushed to help justify the trade or is he just ahead of his time?

16. Brett Oberholtzer (SP, 22, AA, T11) - The other lefty in the system with upside, he seems like a fifth starter or a bullpen guy but he may yet surprise.

17. Jordan Schafer (OF, 24, ML, T11) - Another piece of the Bourn trade, he'll turn 25 next month and hasn't shown the power in the majors to see him as anything more than a stopgap. However, the Braves once saw him as a top prospect so perhaps there is more there.

18. Kody Hinze (1B, 24, AA, FA) - If Wallace flames out, Hinze will have a short window to claim 1B in Houston before Singleton arrives. He hit well at Lancaster (a notorious hitters park) but then so did Koby Clemens (Roger's actual son).

19. Austin Wates (OF, 22, A, D10) and Adam Bailey (OF, 23, AA, D10) - Two very similar stories. Both played four full years of college ball so they are being fast-tracked through the minors. Both hit well in Lancaster and Bailey is now getting a test in Corpus. Bailey is older by six months and has shown more power but less speed.

20. Delino DeShields Jr. (2B, 18, A. D10) - Struggling to hit for average at low A-ball, he has shown both power and speed as the #8 overall draft choice last year. Perhaps he's being pushed through the system. He may find it tough to crack the Astros lineup if Altuve and Springer both turn out to be the real deal.

As you'll note, the pickings are slim at catcher, shortstop and third base. There are also relievers in the system but they tend not to stay in one place too long. Many starters in the minors become relievers in the majors and then there are relievers down there who also get their chance to excel.

Suffice it to say there's no Brad Lidge or Billy Wagner toiling in the minors right now that screams to be a future closer and Mark Melancon, at age 26, is unlikely to remain an Astro far into the decade. Some closer will emerge but, as yet, there's no clue who that could be.

The Astros are not done dealing off veterans but they've already cashed their better chips. Future drafts will bring some players and the Dominican academy may bear some unexpected fruit. For the time being though, these players represent the Astros you'll root for in the coming years. Perhaps a few older holdovers like J.A. Happ and Jason Bourgeois will still be around. It will be a long wait regardless but one which may be the right transition to a winning franchise again.